The precise functioning of the meiotic cell division determines the evolutionary survival of all sexually reproducing species. Much of what is known about chromosome orientation and movement during meiosis has come from careful observation of and experimentation with insect spermatocytes. However, the use of these cells for certain important experiments is limited and will remain so until a means can be found for microinjecting cytoskeletal and other kinds of molecules into them. The proposed research will test the feasibility of microinjection of molecules into living insect spermatocytes. The long-term goal is to develop these spermatocytes, which have large chromosomes, kinetochore microtubule bundles, and spindles, as model cells in which to visualize the turnover of tubulin subunits during initial chromosome orientation and prometaphase and anaphase movement. A simple system for pressure injection which has been highly successful with other cell types will be attempted with insect spermatocytes. Modification of this system will occur as necessary. Various means will be used to anchor the spermatocytes to the substratum and control experiments using various kinds of micropipettes will be performed. In all cases a standard inert fluorescent molecule, FITC-BSA will be the marker for successful injection. Four different species of locally abundant grasshoppers will provide spermatocytes for these trials. Successful injection of FITC-BSA will lead to a series of experiments using DTAF-tubulin and an antibody to it as a probe for tubulin turnover in these cells.